Officials also revealed that the baby - due in the middle of July - will be delivered in the Lindo Wing of St Mary's Hospital in Paddington, London.

The maternity ward is where Princess Diana gave birth to Prince William and his brother Prince Harry. Prince William is expected to attend the birth if his RAF duties allow him to do so, and will take the two weeks' paternity leave allowed by the Ministry of Defense.

Elsewhere, officials asked for "sensitivity" surrounding the birth and said: "[It's a] very personal matter for the Duke and Duchess. But they also know it's a time to celebrate and many will want to share in their joy."

A spokesperson for the Palace asked reporters to "ensure that the normal functions of the hospital are not impeded" by their presence.

Speculation about the sex of the royal baby has been rampant for some time, with rumors that the Duchess is expecting a daughter circulating in March after she appeared to give the game away while meeting a member of the public.